Conceptually, how does replay work in a game?

Question

I was kind of curious as to how replay might be implemented in a game.

Initially, I thought that there would be just a command list of every player/ai action that was t

Answer 1

Dan Bryant

Further, recording random seeds would not be sufficient for rewind support, since random progression is not a reversible procedure without special support in all of the logic relying on the randomness. It's more flexible to record the results of the random operations as part of the event stream.

That's exactly What I thought at first when I was trying to figure out how did they make it so that the game replays always the same each time. With Doom I thought at how random the shoots went :D. Store any random number got used, I found out it could be a solution. That was before I came across a pdf paper about Crysis technology. Some textures noise there and grass or tree disposition, seemed to be using pseudorandomization with fixed reversible seed to make it so you didn't see altered disposition of noise, trees and grass anytime you look!

Avoiding at the same time, to store millions of trees and grass shafts position. Apparently pseudo random sequence can replay the same anytime, as the logic is fixed, to just make a fake statistically random sequence of numbers.